Crown caps



June 8, 1965 J. c. lNGLlS 3,187,919

CROWN CAPS Filed June 20, 1962 C5 c4 35 35a 31 INVENTO JOHN C. IN IS ATTbKIQEYS United States Patent 3,187,919 r CROWN CAPS John Clark Inglis, Toronto, Ontario, Canada, assignor,

by mesne assignments, to Autocrown Corporation Ontario, Canada," an ()ntario The invention relates to crown caps such as are used for capping bottles and other containers containing liquid; such caps find extensive use in the beverage industry for capping bottles of beer and soft" drinks.

A crown cap'normally comprises a metal shell having a central, disc-like portion with a skirt surrounding said portion and provided with corrugations which extend downwardly of the skirt and one or more sealing gaskets within the shell. Prior to applicationof the cap to the bottle, the free edge portion of the skirt is flared outwardly and during application of the cap the skirt is caused to embrace a rounded rib at the top of the bottle neck by contracting the flared-out portion in a die so that the cap grips the neck. To remove such a cap from a bottle it is normally necessary to use a bottle-opener having a flange portion to engage under the free edge of the skirt and a lever arm whereby the skirt may be levered oti the rounded rib by said flange portion to permit the use of the liquid in the container.

Several proposals have previously been made for forming crown caps with lateral finger tabs so that the caps may be removed from the bottles to which they have been applied without the use of a bottle-opener.

It is an object of the presentinvention to provide an directed downwardly of the skirt, the corrugations definr ing external crests and troughs, and at least two uncorru gated portions each located between adjacent series of corrugations and each defining an external trough between said adjacent series, the peripheral width of each uncorrugated portion being greater than the peripheral distance between the crests of two adjacent corrugations in. the same series, the uncorrugated portions lying in the residual sectoral portion of the skirt not constituted by said minor sectoral portion, the skirt being corrugated around its periphery save at the uncorrugated portions and being of sufiicient length around its entire periphery that when the cap is applied to a container all the troughs including the troughs of the uncorrugated portions can' be crimped under the usual external rib around the orifice of the container. Preferably, the peripheral width of each uncorrugated portion is approximately twice the peripheral distance between the crests of two adjacent corrugations in the same series.

According to a second aspect of the invention the free edge portions of the finger tab have the configuration of a U with one arm of the U forming an outward continuation of the tab, the base of the U generally normal to 7 preferably spaced equal peripheral distances from the points where the free edge portions of the finger tab join the skirt. The uncorrugated portions, or two of the uncorrugated portions, may be on radii of the disc-like porice tion which are normal to said diametral plane. Three uncorrugated portions of the skirt may be provided and the third uncorrugated portion may lie diametrally opposite to the finger tab and be bisected by said plane. However it is believedthat the best arrangement is one with but two uncorrngated portions, one on each radius of the disclike portion normal to said plane. portions facilitate removal of the cap from a bottle'by upward pressure on the finger tab. Probably no more than three uncorrugated portions would be desirable. The corrugations of the skirt are preferably brought closer together than in a conventional cap so as not to reduce the total number of corrugations.

An embodiment of the invention will now be described in detail by way of example, with reference to the accompanying drawings in which:

FIGURE 1 is a perspective view of a completed crown cap having a lateral finger tab, the cap. being shown in its condition before it is applied to a bottle;

1 FIGURE 2 is a perspective view showing the underside of the cap of FIGURE 1; t

FIGURE 3 is a plan view of a metal blank from the cap of FIGURE 1 is formed;' a

. FIGURE 4 is a sectional view of a metal shell formed from the blank of FIGURE 3; l

FIGURES 5 to 8 inclusive are sectional views showing the results of successive further operations on the shell of FIGURE 4 to produce the completed cap of FIGURE which 1, FIGURE 8 showing the completed cap;

FIGURE 9is a sectional view identical to FIGURE 8 but with the cap inverted for comparison with FIGURE FIGURE 10 is a sectional view of the completed cap after it has been applied to a bottle; and FIGURE 11,is a sectional view on a vertical plane through the line 11-11of FIGURE 10.

1 A crown cap 39 has a metal shell 30' with a central circular disc-like portion .32 adapted to lie across the orifice at the top of abottle neck 34. A skirt 35 of the shell 30' surrounds the disc-like portion 32 and extends from the periphery of the disc-like portion'and generally normal to the disc like portion. The free edge portion 35a of the skirt is flared downwardly and outwardly, ending in a horizontal portion 35b, and the skirt is corrugated with corrugations C running downwardly from the disc-like portion. As shown in FIGURE 2, each corrugation has an external crest Cc with an external trough Ct at either side. Twenty-two corrugations are provided in the skirt portion and they are divided into two equal groups or series of eleven corrugations each, these series being separated bytwo uncorrugated portions 37 of the skirt. The corrugations of one of the series are labelled C1 to C11 in FIGURE 2, and the remaining corrugations form the other series. i

The shell 30' also includes a lateral finger tab 38 which is generally rectangular in plan view and extends outwardly from a minor sectoral portion of the lower edge ofthe skirt 35. Before the cap is applied to the bottle, the finger tab 38 is generally parallel to the disc-like portion 32, the finger tab being approximately in the plane of the portion 35b of the skirt. The free edge portions of the tab are reinforced and smoothed by being rolled into'the configuration of a U with one arm 38a (FIG. 8) of the U forming an outward continuation of the tab in the general plane-of the tab, the base 38b of the U gen erally normal to the tab and :the other arm. 380 of the U generally parallel to and below the tab. Since the free edge portions are rolled under the tab the latter has a neat appearance when viewed from above. The corners of the tab are rounded, as at 38d, to prevent the tab' from causing injury or damage. I

As mentioned above, the corrugations C are arranged The uncorrugated' tinned into the .figner tab ,to reinforce the latter.

in two series" of eleven corrugations each and the series are separated by two uncorrugated portions 37 of the skirt, each uncorrugated portion having a peripheral width greater than the peripheral distance between the.

crests Cc of two adjacent corrugations in the same series. In the cap illustrated, the peripheral width of .each uncorrugated portion 37 is twice the peripheral distance between the crests of two adjacent corrugations in the same series. Thus, each of the twenty-two corrugations subtendsan angle .of at the centre of the disc-like portion 32., and each of the llncorrugated portions subtends an angle of about As mentioned above, probably no more than three uncorrugated portions would be desirable; three .uncorrugated portions each subtending an angle of 30 would result in not more than one-quarter of the periphery .of the. skirt being uncorrugated. The uncorrugated portions. 37 he in the residual sectoral portion .of the skirt not constituted by the minor sectoral portion from which the finger tab 38 extends. The finger tab is bisected by a diametral plane of the central disc- C11 are provided in each portion of theskirt lying between the finger tab and one .of the uncorrugated portions 37. The fivecorrugations C4 ,IC5, C6, C7, C8 in the minor sectoral portion and the six corrugations C1, C2, C3, C9, Cw, Cillat the sides thereof form a first series of eleven corrugations whereas the remaining eleven corrugations form a'sec'ond series in an arcuate portion of the skirt lying generallyopposite to the finger tab. The'series of corrugations are separated 'by the two uncorrugated portions 37 of the skirt, the uncorrugated portions 37 defining external troughs between the two series of corrugations. Save at the uncorrugated portions'37 the skirt is continuously corrugated around its entire periphery.

Before the cap is appliedto its bottle, theportions 35a and 35b of the whole of the skirt, including its uncorrugated portions, flare outwardly but, afterthe skirt has been contracted .inthe capping operation, thev uncorrugated portions, asshown in FIGURE 11, extend generally normal to the disc-like portion 32 with a slight bulge where they embrace the rib 39 at the top of the bottle neck, as dothe troughs Ct of the corrugations. As can be seen "fromFIGURES 10 and 11, the skirt is of sufficient length aroundits entire periphery that all the troughs Ct, as .well as the troughs defined by the uncorrugated portions 37, can be crimped under the external rib 39. The .crown'cap is completed by a cork or polyethylene gasket d0 secured to the underside of thedisc-like portion 32 within the skirt. If desired, when a cork gasket is provided it may be overlaid with a foil disc to prevent the liquid in the container from contacting the cork. The gasketillustrated isa polyethylene liner having concentric ridges a near its peripheryto press against the top .of the bottle. lt'has been found that the crown cap will hold .-a pressure of 28 psi. in the bottle for an indefinite period; infact, since the uncorrugated portions 37 embrace and arecrimped under the rib39 they improve the grip .of the cap on the bottle against upward pressure fromwithin the bottle. 7

'As mentioned above, prior to applying'the cap to a bottle, the :finger tab 38 is generally parallel to the disclikelportion'32 and the portions 35a and 35b of the skirt a-re flared outwardly. When the cap is placed on a bottle, the skirt is contracted and is caused to embrace the rib 39 at the top of the neck by conventional means well known in the art, and simultaneously the finger tab is bent to incline downwardly at an angle of between 15 and 35 to the disc-like portion 32.

To open the bottle, finger pressure is applied to the undersurface of the finger tab thus forcing the minor sectoral portion of the skirt adjacent to the finger tab over the rib 39 at the top of the bottle neck. 'This disengagement or the skirt from the rib'is found to be facilitated by the presence of the uncorrugated portions 37. They cause the corrugations C1, C2, C3, C9, C10 and C11 (located between the finger tab and the uncorrugated portions which are spaced from the tab) to spread temporarily as the cap is lifted, and the portions 37 tend to strip away from the rib 39. Moreover, due to the rolled edges 38a 38b, 38c and corrugations C4, C5, C6, C7, C8 of the finger tab, the latter is of sufficient strength to transmit the leverage required to disengage the skirt from the bottle neck rib. The downward inclination of the finger tab is necessary since the latter moves from its FIGURE 10 position upwardly more rapidly than the cap is disengaged from the neck of the bottle.

Provided that the cap has not been unduly deformed during removal of the cap, the latter may be re-used by pressing it back on to the bottle although, of course, the seal will not be as good as that obtained when the cap is applied to the bottle in a capping machine. If desired, a third uncorrugated portion may be provided in the residual sectoral portion of the skirt at a location diametrally opposite to the finger'tab. When three uncorrugated portions are provided it is apparent that the corrugations are divided into three series of uncorrugated portions.

The crown caps described above may be made by a method described inco-pending patent application No. 203,870, filed concurrently herewith. Briefly, however, a fiat blank 38(FIG. 3) is stamped from a sheet of metal, the blank being circular save for alateral tab 38 which is to form the finger tab. Theblank 3%" is dished to form a sht-Zllfifi' (see FIG. 4) having the central disc-like portion 32 and corrugated skirt 35, but the tab 33' remains uncorrugated. Next (FIG. 5) the corrugations C5, C6 and C7 are formed in the tab 38' and the free edge portions of the tab are bent generally normal to the tab. Then (FIG. 6) the freeedge portions of the tab are fiattened to form the rolled U-shaped reinforcement 38a, 38b, and 380 and complete the finger tab 38. To provide a polyethylene gasket, a drop 40' of liquid polyethylene is metered into the shell 39' (FIG. 7) and is there moulded and cured to form the gasket or liner 40 (FIG. 8), completing the ,cap 30.

What I claim as my invention is:

1. A crown cap adapted to seal an orifice of a container by embracing an external rib around the orifice, the cap having a disc-like portion, a skirt surrounding said portion and extending from'the periphery thereof, and a lateral finger tab extending outwardly from a minor sectoral portion of the lower edge of the skirt, the skirt having at least two series of corrugations of which each corrugation is directed downwardly of the skirt, the corrugations defining external crests and troughs, and at least two uncorrugated portions each located between adjacent series of corrugations andeach defining an external trough betweensaid adjacent series, the peripheral width of each uncorrugated portion being greater than the peripheral distance between the crests of two adjacent corrugations in the same series,'-the uncorrugated portions lying in the residual sectoral portion of the skirt not constituted by said minor sectoral portion, the skirt being corrugated around its periphery save at the uncorrugated portions and being of suificient length around its entire periphery that all the troughs including the troughs of the uncorrugated portions can be crimped under said external' rib when the cap is applied to the container.

2. A crown cap as claimed in claim 1, wherein the free edge portions of the finger tab have the configuration of a U with one arm of the U forming an outward 5 continuation of the tab, the base of the U generally normal to the tab and the other arm of the U generally parallel to the tab.

3. A crown cap as claimed in claim 1, wherein some of the corrugations are located between the finger tab and the uncorrugated portions of the skirt.

4. A crown cap as claimed in claim 3, wherein uncorrugated portions are spaced equal peripheral distances from the edges of said tab.

5. A crown cap as claimed in claim 4, wherein said uncorrugated portions are diametrically opposite each other.

6. A crown cap as claimed in claim 5, wherein the diametrically opposed uncorrugated portions are the only uncorrugated portions of the skirt.

7. A crown cap as claimed in claim 6, wherein the peripheral width of each uncorrugated portion is approxi- 6 mately twice the peripheral distance between the crests of two adjacent corrugations in the same series.

8. A crown cap as claimed in claim 4, wherein not more than one-quarter of the periphery of the skirt is uncorrugated.

References Cited by the Examiner UNITED STATES PATENTS THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, Examiner. 

1. A CROWN CAP ADAPTED TO SEAL AN ORIFICE OF A CONTAINER BY EMBRACING AN EXTERNAL RIB AROUND THE ORIFICE, THE CAP HAVING A DISC-LIKE PORTION, A SKIRT SURROUNDING SAID PORTION AND EXTENDING FROM THE PERIPHERY THEREOF, AND A LATERAL FINGER TAB EXTENDING OUTWARDLY FROM A MINOR SECTORAL PORTION OF THE LOWER EDGE OF THE SKIRT, THE SKIRT HAVING AT LEAST TWO SERIES OF CORRUGATIONS OF WHICH EACH CORRUGATION IS DIRECTED DOWNWARDLY OF THE SKIRT, THE CORRUGATIONS DEFINING EXTERNAL CRESTS AND TROUGHS, AND AT LEAST TWO UNCORRUGATED PORTIONS EACH LOCATED BETWEEN ADJACENT SERIES OF CORRUGATIONS AND EACH DEFINING AN EXTERNAL TROUGH BETWEEN SAID ADJACENT SERIES, THE PERIPHERAL WIDTH OF EACH UNCORRUGATED PORTION BEING GREATER THAN THE PERIPHERAL DISTANCE BETWEEN THE CRESTS OF TWO ADJACENT CORRUGATIONS IN THE SAME SERIES, THE UNCORRUGATED PORTIONS LYING IN THE RESIDUAL SECTORAL PORTION OF THE SKIRT NOT CONSTITUTED BY SAID MINOR SECTORAL PORTION, THE SKIRT BEING CORRUGATED AROUND ITS PERIPHERY SAVE AT THE UNCORRUGATED PORTIONS AND BEING OF SUFFICIENT LENGTH AROUND ITS ENTIRE PERIPHERY THAT ALL THE TROUGHS INCLUDING THE TROUGHS OF THE UNCORRUGATED PORTIONS CAN BE CRIMPED UNDER SAID EXTERNAL RIB WHEN THE CAP IS APPLIED TO THE CONTAINER. 